A known type of stage light comprises a main body extending along a longitudinal axis; a light source, arranged inside the main body at a closed end of the main body and adapted to emit a light beam substantially along the axis; an objective lens arranged at an open end of the main body opposite to the closed end along the axis; and light beam filtering and/or shaping means arranged between the light source and the objective lens so as to intercept the light beam.
The light beam filtering and/or shaping means are adapted to obtain particular effects on the light beam, and generally comprise light beam coloring assemblies, a diaphragm, which is simply an opaque disk having a central hole of variable dimensions, which limits the diameter of the light beam emitted by the stage light, and gobos, which are disks, typically made of stainless steel or glass, in which a motif or a shape adapted to generate a light pattern, when the gobo intercepts the light beam, is obtained.
The objective lens is arranged substantially orthogonally to the axis of the main body, and is moveable along the axis to allow to adjust the position of the focus of the lens with respect to the light beam filtering and/or shaping means.
However, the diameter of the objective lens of this type of stage light is necessarily limited by the presence of a relatively cumbersome support ring of the objective lens as it must accommodate at least part of the objective lens position adjusting mechanism. The size of the objective lens inevitably also limits the size of the light beam emitted by the stage light, with evident disadvantages from the point of view of stage light efficiency.